From ec22d26e38624133a6039b2f90389d35d4cd20a1 Mon Sep 17 00:00:00 2001
From: sgourdas <jim31700@gmail.com>
Date: Mon, 23 Sep 2024 19:18:57 +0300
Subject: [PATCH] Add ip availability check in server start

---
 src/server/internalServer.cpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/server/internalServer.cpp b/src/server/internalServer.cpp
index cee7c194a..06ff30565 100644
--- a/src/server/internalServer.cpp
+++ b/src/server/internalServer.cpp
@@ -85,6 +85,19 @@ namespace kiwix {
 namespace
 {
 
+bool ipAvailable(const std::string addr)
+{
+  auto interfaces = kiwix::getNetworkInterfacesIPv4Or6();
+
+  for (const auto& [_, interfaceIps] : interfaces) {
+    if ((interfaceIps.addr == addr) || (interfaceIps.addr6 == addr)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 inline std::string normalizeRootUrl(std::string rootUrl)
 {
   while ( !rootUrl.empty() && rootUrl.back() == '/' )
@@ -484,6 +497,11 @@ bool InternalServer::start() {
       return false;
     } 
 
+    if (!ipAvailable(addr)) {
+      std::cerr << "ERROR: IP address is not available on this system: " << addr << std::endl;
+      return false;
+    }
+
     m_ipMode = !m_addr.addr.empty() ? IpMode::IPV4 : IpMode::IPV6; 
   }